The prior art includes many patents on edge position detectors and web guiding apparatus and the steel processing industry presently uses apparatus of this general type for maintaining a running strip on the centerline of the processing line. Much of this apparatus includes hydraulic cylinders and circuitry to effect shifting of the strip from a deviated position back to the centerline of the strip processing line and, although such apparatus operates satisfactorily, it is clostly to install and maintain.
My improved apparatus utilizes air cylinders to effect shifting of the steering roll and thereby reduces the size, cost, and complexity of the web guiding apparatus now in use. In the prior art hydraulic systems, costly hydraulic pumps, accumulators and cylinders are required and this cost is eliminated in my apparatus since most shops have an air compressor and it is a simple matter to run a line therefrom.
Because of the use of air cylinders, my improved apparatus quickly shifts the steering roll from one position to another, and the amount of shift may be regulated by adjustable stops. This is a decided advantage since strip being pulled through an annealing furnace should have only a small angle of adjustment to avoid stretching of the strip an undue amount along one longitudinal margin.